Set functions

remote control LB-721 used for programming functions of a panel
LB-722C.

The set is used for measurement and regulation of relative humidity
and temperature in the rooms (i.e. warehouses, climate chambers) and
signaling of alarm limits exceed.

The reading - control panel LB-722C receives from the attached to it
hytherograph
LB-710
the relative humidity and temperature measurement results in a chosen
point of an object. Basing on it the panel LB-722C through one of 3
transmitter outputs realizes the following configuration functions:

after exceeding one set (up or low) temperature threshold with a
hysteresis +/- 0,5°C it can turn off or on a heating or cooling
device,

after exceeding one set (up or low) relative humidity threshold
with a
hysteresis +/- 0,5% it can turn off or on a humidifying or drying
device,

after exceeding one of the set thresholds: high or low
temperature or humidity it can turn on an alarm signaling,

The panel LB-722C registers in its memory the last 64 relative
humidity or temperature results (configuration) in set 1 hour periods
of time. The actual measurement results stored in the device's memory
cover the last 64 hours and the device settings are shown on two four
digit LED screens (digit height 12 mm). The screens can work
independently in different work modes. In the basic mode the actual
humidity and temperature measurement results are shown. When
programming the device one of the screens shows a parameter being set
and the other one an adequate description (symbolic parameter marking).
A similar situation takes place when scrolling the memory, which
contains the measurement results (in such case one of the screens shows
– symbolically - time and the other one stored measurement result).

The remote control (programmer) LB-721 is a transmitter used for
programming the panel LB-722C settings using an optical link
(IR).The programmer LB-721 is a small, portable ("pocket")
device, powered from one battery 9 V (6F22). It is equipped with eight
key button membrane keyboard, which is very easy to read. Six of those
key buttons switch the work mode of the servo's screens
and the other two are used for increasing or decreasing a parameter
when programming. The following are especially regulated:

switch on or switch off thresholds of the temperature and
humidity executive devices,

way of controlling the executive devices (switch on/ off after
exceeding the set thresholds),

up and low humidity and temperature alarm thresholds,

type of the registered measurement(humidity or temperature).

The settings are stored in a panel's nonvolatile memory LB-722C (the
values last chosen stay the same after the power supply is switched
off).

The special way of programming the device by (using a special remote
control) protects the settings from any change. It is impossible to
make any unauthorized changes since there are no programming key
buttons. The programmer’s work range is approximately1 m.

Set construction

Thermometer - hygrometer
LB-710 is
an
independent device equipped with a capacity relative humidity sensor
and a sensor Pt1000 used for temperature measurement. Thermometer –
hygrometer
LB-710
has a microprocessor, which realizes measurement algorithms by taking
into consideration (non-linear) characteristics from both sensors as
well as calibration data stored in a nonvolatile memory. The
measurement results are transmitted to a panel LB-722C in a digital
form with the speed approx. 300 bods and a repetition period
approximately 2 s. The current interface used in the device powers the
measurement device. This type of solution guarantees simple
hytherograph - panel connection, using only two cables. Beside both
devices can be placed quite far from each other (distance limited by
the connection cable loop resistance - less than 100 ohm). Since the
transmission speed is quite slow and current interface standard, high
resistance to outside interferences using a cable of any type
characterizes the connection. The connection is resistant to changing
the cable endings (polarity).

During periodical calibration (confirmation) of the hytherograph
LB-710 a two-way
digital transmission is used. During calibration a set of coefficients
grading the results gets stored in the nonvolatile memory of the
hytherograph
LB-710M.
The regulation elements (potentiometers and trimmers) - that are often
the source of problems (thermal instability, noises and clicks, random
setting intervention etc.) were eliminated in such way.

Each thermometer - hygrometer (upon
a request) can have an individual
calibration certificate
issued by the LAB-EL
Calibration
Laboratory or from the Central Army Metrology Center
in Zielonka. Thermometer – hygrometer
LB-710
received the certification of type RP T 95
77 issued by the President of Central Measurement Office in Warsaw.

The panel LB-722C is equipped with a digital output, which transmits
the actual temperature and humidity results with the speed of
approximately 300 bps with time intervals approximately 2s. This output
works in a standard similar to a hytherograph interface
LB-710, what allows
on simple creation of a computerized monitoring system of the
environmental conditions in many rooms. Such system can include any
number of hytherographs
LB-710M
as well as panels LB-720C.

A simple system with one or two hytherographs or servos can be
obtained by connecting them to COM1 / COM2 computer ports through
IBM-PC computer using conversion signal systems (current – voltage
LB-371) produced by
the LAB-EL company. Greater number of system elements can be attached
using a concentrator
LB-731 produced by
the LAB-EL company.

The construction solution used in all devices assure obtaining wide
scope of work temperatures (optionally in the M version - up to maximum
-40..+70 °C). They also assure high reliability and resistance to
interferences. All three devices (
LB-710,
LB-722C,
LB-721) were built basing on the microprocessors especially accustomed
to work in such conditions. All plastics used in making the casings
resist thermal risks at least in the scope of temperatures
-40..+80°C.

Technical data

SCOPE OF WORK TEMPERATURES
AND MEASUREMENT

temperature

-40..+85 °C

humidity

10..95 %

MEASUREMENT INACCURACY

temperature

+/- 0.1 °C,
+/- 1 last digit

LB-710

humidity

+/- 2.0 %,
+/- 1 last digit

in the scope of 10...90%

+/- 4.0 %,
+/- 1 last digit

outside of the scope 10...90%

LEVEL REGULATION

Regulation and alarm scope of
regulation

humidity

0..99,9 %

temperature

-40...+85°C

Regulation levels hysteresis

+/- 0,5 %

RECOMMENDED CONSTANT WORK
CONDITIONS *)

Scope of temperatures

0..40°C

Scope of humidity

20..80%

Level of environment corrosion aggressiveness accord.
PN-71/H-04651

B

*) - Going beyond recommended constant work conditions (i.e. when
installing the device in the open space) requires using additional
protection means for the device's electronic part so that water out
dropping does not start inside of the device (protecting the electronic
part with silicone or using an additional external case).